LocostUSA.com

Using any type of rule limited racing class as an example of how something is superior to something else is false logic.
The Only reason supermodified use beam front axles is rules, just like the only reason F1 cars run 13" rims. They work as good as they do because they have been developed for 30+ years. These vehicle are VERY fast, and work really well, and at least initially with less tuning, switching a supermodified to IFS, or a F1 car to 17" rims would produce a slower car, but long term I'm sure rules removed those vehicles would develop away from what the rules dictate. Rules are not set up because the rule writers know what is the fastest way around a racetrack. It's because they want to manipulate either cost, complexity, speed, or competitiveness. The cars get faster over time as all supporting products (brakes in F1 specifically) advance to meet the rule book. Because of this harmony that exists in popular racing classes, the things they are rule required to use may SEEM to be the best clean slate solution, but often they are not.

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MG midget bodied Locostish car in progress

Actually over the years there have been attempts to run supers and sprints with independent suspension. The straight axle has won out in these cases due to simplicity and light weight. No less than karl kinser tries to develop a independent front sprint car and had no luck with it. When I went to oswego many years ago there were teams playing with independents and there still are, but its not the rule book stopping development.
The original question was whether a straight axle was feasible and it definitely is.

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The biggest thing in motocross.

Hello,

I was kinda thinking on the lines of something simple like

http://www.speedwaymotors.com/Dropped-G ... 27040.html

And even a straight axle not under the bottom rail but over the bottom rail. Over the bottom rail makes all kinds of lowering possibilities come up. I have heard of folks building their own straight axles and they are trully Lo-cost this way. I would be nice to see a car with a straight axle built with all the control/hairpin rods hidden inside the chassis instead of on the outside. Maybe even a front axle out of a sixties model econoline van. A lot of strait axle kits used the econoline van spindles. Nuthin looks pertyer than a polished up and dropped straight axle in a open wheeled car. Just think if we went straight axle in the locost we can even change the frame some. Using the straight axle would allow us to build the bottom rail like we do the top rails. We could make the bottom rail so it would not have to be as narrow in the front. This could make the side pannels not be so wavey looking and have a cleaner look. I'm just kicking these ideas out there for entertainment, not really to change the Locost completly. Anyone go to speedway and look at the 1927 Track T noses there?


Mark

It seems that the commercial "straight" axles, for the most part, have a drop center. There is one listed for sprint cars that is straight, but is only setup for brakes on one end.

I have been thinking about a straight tube with the knuckles dropped down to allow the axle to ride inside the frame. Problem is, even though I am a machinist, I don't have access to a few of the toys I would need to machine the blocks that I would need to weld in the ends of the tube. Need a 15" LeBlond lathe and a #3 horizontal mill and I could make the parts, can even visualize teh reqired setups...

Camber would be machined into the ends of the axle and caster could be adjusted by just rolling the axle back a degree or 2 at a time until it handled right. Might have to play with the kingpin to spindle angle, but I don't see that as being all that hard to do either. Any sources on information as to existing spindles/kingpins/bearings that could be used?

howdy mr cleaver, talk about bringing back old school technology!! trunions, kingpins and sliding joints, re-arced front beams, oh my! back in my fathers day (when they still rode dinosaurs to work) one of the tricks was to bend the beam axle to get it to behave the way you wanted or to repair damage due to the tree or ditch taking an intimate interest in you. some repair shops even had a jig for rebending the front axle and a few early service manuals had references and instructions on how and how much to do it for a desired effect. (heat and then use blocks, chain, comealongs and jacks. mild steel after all) sometimes ignorance is a blessing, these pioneers did a lot of stuff because there was no one telling them "it'll never work" and science came in a distant second. quite bouncy for what we consider comfortable nowadays but still very much a dedion axle without the center pumpkin. if the axle is in front of the leading edge of the body or if theres nothing in its travel path inside the body i can't think of a reason why the axle couldn't be above the bottom of the frame. visual appearance dictating form...... sounds real familiar, why else put fake gorilla fur on a vega station wagon then go sideways down the track? (at least i hope its fake fur )

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"There are times when a broken tool is better than a sound one, or a twisted personality more useful than a whole one.
For instance, a whole beer bottle isn't half the weapon that half a beer bottle is ..." Randall Garrett

Straight axles are fairly simple if you stick to early Ford or Chevy spindles. Really, only three pieces of tubing.

Center tube, which in this app can be straight, is usually 1 3/4" .250 wall . I have seen Chrome moly, but that's not necessary. The ends are just more tubes, set at an angle on the main tube to accommodate KPI. The inner diameter on a Ford is .813" to hold the kingpin.





A draglink connects the two spindles via the steering arms. Then the steering system moves one or the other spindle. The specs for building these things are out there.

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Jack Collins

minimalism at its finest, a cross beam in front and a single rod for input on the left spindle, hide everything else under the bodywork with the beam crossing thru the body. track t nose for sure

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"There are times when a broken tool is better than a sound one, or a twisted personality more useful than a whole one.
For instance, a whole beer bottle isn't half the weapon that half a beer bottle is ..." Randall Garrett

I helped a guy bend a Ford front axle on a dirt track car using instructions from a ~1953 "Honest Charley" catalog! Nothing like doing delicate alignment work with a cut'n torch for the heat and a sledge hammer!

http://www.honestcharley.com/

I couldn't tell much difference (if at all) in a test drive because the car was in a slide most of the time anyway. Especially after they watered the track down.

[edit]
1946 Ford front alignment
Caster: +4.5 to +9°
Camber: +1/4 to 1°
Toe in: 3/32"
King pin angle: 8°
Toe out on turns: Outer wheel, 20°, inner wheel 23-24°

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"My junk is organized. At least is was when I put it wherever it is." -olrowdy
Completed building GSXR1000 CMC7, "Locouki"
Website: http://projekt.com/locouki/

Their are current and past competitive IFS Supermodifieds, you can use what you want in the rules.





And this is Joe Grunda who has just celebrated his first win since 1998 - the win in 1998 was with a fully independent car and after 12 years he is back to a beam...



Makes me laff that people try hard to design a successful IFS and then try as hard as they can to make it perform like a beam does out of the box. > (the LOL smiley bites).

kf2qd, look around the 600 Racing website/catalogue for some spindle ideas - Speedway stuff is cheap too.

Yes but you have to admit that this type of car that only turns left on what are realistically very smooth tracks is a bad model to use an example to how to properly design a road going vehicle. Now if you are making a supermod lotus 7 that will run on smooth tracks and only turn left, I'd for sure use those as inspiration..

I'm not saying a lot can't be learned form all classes of racing, nor am I implying that anyone who designs/engineers/works on a successful racing car of any class is in any way inferior to anyone else. I'm just saying that you have to be careful about what you assume translates from the track to the street. I'm not going to use a SCORE truck as a basis for engineering a F1 car, however I may learn something from packaging, or materials on that SCORE truck so it's worth being made aware of.

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MG midget bodied Locostish car in progress

Sorry nocones but you obviously have never raced on oval short tracks. Smooth is not the accurate way to describe most of them.

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The biggest thing in motocross.

Here's a little 3D sketch i made for a drop axle design. Weld in pieces in the end of a tube. - Just need the machine shop...

Turning left only has nothing to do with tyre contact patch for a beam as both sides are flat 99% of the time but ironically and totally against your stance it has everything to do with IFS - you can set up the right and left cambers/caster etc. as they do in NASCAR and INDY to get a very good contact patch for only left handers but if you need to turn right as well then it's back to a compromised setup.

Again and ironic that some of the shitty handling cars around that I see with wheels in all sorts of awkward angles are based on F1/racing designs and that includes here - I'll post a picture when I get home as an example tonight. The amount of cars that are built on track tech/theory around here and everywhere else rather than building for the real world street is ridiculous. Miniturisation of SCORE designs would probably suit more builders here than F1 designs.

You make a point that beams are well developed for speedway but I counter that for IFS as it was well developed because of bad roads 70 years ago and the IFS gave a far superier ride to heavy cast iron beams - since then of course the car has been totally developed and designed around the IFS but even today it's still a compromised mystery/black art how to get one to work properly where as out of the box a beam will offer 95% of it's potential immediately.

And lastly unsprung weight is hugely overated for our needs not that I can't build a beam that isn't lighter than say a standard Toyota suspension package.

One thing you're up against is consistency side to side. It is difficult to get precision and you may find that your caster and KPI are not the same left to right which will spoil your drive - pullling left or right, tramlining etc.

The race car article I linked somewhere above had a slip joint in the center and both sides were adjustable for KPI. You may want to incorporate some adjustability feature into your design to allow for this, maybe bolt on kingpin tube ends with bolt holes slightly slotted. The shorter your kingpin tubes the harder it will be to control error too but you may be bound by what pins you can buy commercially.

I read an article once about a guy who built his beam, experienced these problems and ended up buying one of the reputable Hot Rod shops beams and he reported it was like night and day, so much better. From this I gather the good shops pay a lot of attention at jigging/welding stage - a laser light beam may be the answer.

You are overcomplexicating your axle design with that fancy machined part.

All you need is a tube welded on the end of another tube. In the real world, you jig these things, tack, measure, adjust, then weld. Then you measure again. If they are a bit off, you break out the big adjustment bar and you tweak it into shape.

Very minor variations from side to side don't really show up in real world driving feedback. If your KPI or caster is off by a quarter degree, I don't think you would ever notice. Bushings can deflect far more than that and your tires will "soak up" an awful lot of it.

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Jack Collins